Insomnia is a major mental health symptom related to depression, sleep loss, sleepiness, mistakes, accidents, irritability and anger. The Restless Legs Syndrome (RLS) is a common sensory-motor disorder associate with profound insomnia and in population studies has been also associated with increased risk of hypertension. Periodic limb movements in sleep (PLMS) occur commonly in RLS patients and also in many of the elderly. It has been assumed that the PLMS produce insomnia and when not occurring secondary to another sleep disorder are part of the periodic limb movement disorder (PLMD). The evaluation of the PLMS has been complicated by several factors including the large night-to-night variability and the lack of quantification of either the amount of the movement or the degree of the arousal associated with the movement. Ambulatory methods need to be developed for multiple-night quantification of the leg movements and the arousals associated with them, particularly the autonomic arousals. These arousals may contribute significantly to development of hypertension. This project will develop such a fully ambulatory leg activity monitoring system (LAMS) and evaluate the data for identification of EEG arousals plus overall quantification of the degree of arousals with the leg movements. The quantifications for RLS patients will be compared to that for patients with PLMS without any other sleep disorder to explore diagnostic utility. The quantification of the arousals with the PLM also permits evaluation of their significance for cardiovascular risk. Phase II will involve enhancing the miniaturization, incorporating event detection software in the unit, and conducting multi-center validation trials including a comparison of the leg activity for RLS vs. PLMS without RLS. This system will provide for the first time an opportunity to analyze PLMS and the associated autonomic arousal as they naturally occur over several nights. These should prove useful both for diagnosis and for evaluation of treatment of RLS patients. [unreadable] [unreadable]